One of the most common patient complaints involving dental procedures is the constant irritation of the corners of the patient's mouth by saliva extractors and other dental instruments. When, for example, a saliva extractor is hung in the corner of the mouth for a significant period of time, the rubbing and pressure can cause small splits that may take days or even weeks to heal. Other dental instruments pressing against the corners of the mouth also may irritate the corners and cause painful and difficult-to-heal sores. Medical instruments used during medical procedures can result in similar problems.